Heat the milk in a small small saucepan or microwave. It should be lukewarm, but not hot.
In a large mixing bowl, mix the flour, sugar, yeast, salt and lukewarm milk and knead for 3 minutes. Add the oil and knead for further 2-3 minutes.
Shape the dough into a ball, sprinkle the bowl with flour and place into a bowl. Cover with cling film and place in a warm place for 1 hour or until doubled in size.
Line a muffin tray with paper cases. Once the dough has doubled in size, using two spoons, gently scoop the dough from the bowl and into the paper cases. Squeeze in a couple of rhubarb slices and raspberries on top of each one
For the crumble
To make the crumble, simply rub the butter into the flour using your fingertips to make a light breadcrumb texture, then add the sugar and a pinch of salt.
Sprinkle each muffin with the buttery crumble and place the muffins aside for the last 15 minutes. This will give them a chance to rise slightly. Meanwhile preheat the oven to 180 degrees / gas mark 4.
Bake for 25 - 35 minutes, until the top of the muffin is golden brown.
